JP3603173B2 - Liquid filled type vibration damping device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-sealed type vibration damping device capable of obtaining a vibration-damping effect based on the flow action of a fluid (liquid) sealed therein, and is particularly exhibited with the flow of a liquid. The vibration isolating characteristics can be switched to a plurality of stages by a simple mechanism driven by the engine suction negative pressure, and a rubber insulator forming a main spring of such a vibration isolating device is provided around the rubber insulator. The present invention relates to a liquid filled type vibration damping device in which a liquid chamber is provided so that the dynamic spring constant is not affected by heat.
[0002]
[Prior art]
Among the vibration isolators, especially in the case of engine mounts for automobiles, the engine, which is the power source, is used under various conditions from the idling operation state to the maximum rotation speed. Therefore, it must be able to handle a wide range of frequencies. In recent years, engine mounts have been tuned for the purpose of cutting off noise caused by vibration in a relatively high frequency range. In order to cope with such a plurality of conditions, a liquid chamber is provided therein, and further, the liquid chamber vibrates at a specific frequency and is driven by a negative suction pressure of the engine. A vibration device having a simple mechanism is provided so that various vibrations such as idling vibration can be cut off, for example, as shown in FIG. 4, has already been filed by the present applicant. (See Japanese Patent Application No. 8-287524).
[0003]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional one, the insulator 20 which forms a main spring is provided with the insulator 20 in a naked state in an engine room, which is responsible for vibration isolation together with the anti-vibration mechanism 10. is there. Therefore, it is affected by high-temperature heat from the engine and is exposed to oxygen in the air. As a result, due to thermal deformation or oxygen deterioration, the dynamic spring constant changes so as to increase. This is because the dynamic spring constant of the liquid-filled vibration isolator tuned according to the frequency of the target vibration, such as idling vibration, engine shake, and muffled sound, is initially set. It will fluctuate from the state, which is not preferable. Therefore, as a countermeasure, one of the measures is to provide a so-called feedback control means for measuring a change in the dynamic spring constant and maintaining the optimum tuning state by reflecting the result in a control system. Alternatively, a method is conceivable in which the initial tuning is performed widely in a state where the variation of the dynamic spring constant is expected in advance. However, the former method has a problem that the control system is complicated and the cost is too high. On the other hand, the latter method has a problem that the tuning cannot be performed optimally and the performance of the apparatus cannot be fully utilized. Therefore, in order to solve such a problem, a feed-forward control type automatic control engine mounting device (ACM) capable of maintaining an initially optimized tuning state for a long period of time. It is an object (problem) of the present invention to provide.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has taken the following measures. That is, in the invention of claim 1, wherein the upper connecting member attached to the vibrating body, and a lower connecting member attached to the vehicle body, the vibrations from the vibrator be in between these upper connection member and the lower connecting member An insulator that absorbs and shuts off, and a main chamber that is provided in series with the insulator and that is filled with a liquid that is an incompressible fluid, and that the liquid flows through the main chamber and the orifice. auxiliary chamber connected to, even the main chamber of a by atmospheric pressure and the negative pressure intended to be formed via a diaphragm, the equilibrium chamber or al any one of one of which is formed to be introduced A vibration isolating mechanism, switching means for performing a switching operation to introduce either negative pressure or atmospheric pressure into the equilibrium chamber of the vibration isolating mechanism, and the switching means And controls the switching operation between a state continuously introducing one of a negative pressure and the atmospheric pressure in the equilibrium chamber, in a state of being synchronized with negative pressure and the atmospheric pressure to the vibration of the vibrator to the equilibrium chamber Control means for switching between alternately introduced states , wherein a liquid chamber is provided outside the insulator, and the outer periphery of the liquid chamber is formed with excellent heat resistance. In this case, the elastic diaphragm is provided.
[0005]
By adopting such a configuration, the device of the present invention exhibits the following operation. That is, in the device of the present invention, since the rubber-like elastic diaphragm having excellent heat resistance is provided on the outside of the insulator, the vibration isolator is installed in a high temperature such as an engine room. In this case, the insulator portion made of the vibration-proof rubber material is not directly exposed to high temperature. In addition, since the liquid chamber is provided around the insulator, the surface of the insulator does not directly contact oxygen in the atmosphere. That is, the configuration is excellent in oxygen barrier properties. Therefore, as for the insulator forming the main spring in the present invention, it is not necessary to particularly consider heat resistance and oxygen deterioration, and only the low dynamic spring characteristic may be pursued. As a result, it becomes possible to adopt a vibration-proof rubber material mainly composed of ordinary natural rubber, and it is possible to suppress an increase in the dynamic spring constant with respect to high-frequency vibration.
[0006]
In addition, a portion of the insulator forming the main spring in the vibration isolator is covered with a heat-resistant elastic diaphragm or the like, and its dynamic spring constant varies due to the influence of heat in the engine room. There is no. Therefore, even when used for many years, the initial setting conditions tuned for the purpose of isolating vibrations do not shift (disappear). As a result, on the basis of such a dynamic spring constant, various vibrations including an idling vibration are cut off. Hereinafter, these will be described.
[0007]
First, with respect to the cutoff of the idling vibration, by operating the switching means, a negative pressure or an atmospheric pressure is alternately introduced at a specific frequency into an equilibrium chamber provided at a lower portion in the main chamber. I do. That is, by operating the switching means at a specific frequency, the pressure (volume) in the equilibrium chamber is changed, whereby the hydraulic pressure fluctuation in the main chamber caused by idling vibration input through the insulator. So that it absorbs. As a result, the dynamic spring constant of the spring system formed by the insulator and the main vibration isolating mechanism can be reduced. As a result, idling vibration is cut off.
[0008]
Next, with respect to the engine shake which is a vibration having a lower frequency than the idling vibration, the liquid is caused to flow through the orifice connecting between the main chamber and the sub-chamber. Shall be absorbed and blocked. That is, since the vibration related to the engine shake has a frequency of about 10 Hz, it is difficult to cut off the vibration by reducing the dynamic spring constant. Therefore, in the present invention, a constant negative pressure is continuously introduced into the equilibrium chamber forming the vibration isolation mechanism, the diaphragm forming the equilibrium chamber is pulled down, and the volume of the equilibrium chamber is reduced. Set to zero state. This prevents a change in volume in the equilibrium chamber. In such a state, when the vibration from the vibrating body is propagated to the insulator, the lower surface of the insulator vibrates according to the vibration, and the liquid in the main chamber is positively moved to the sub-chamber side. Operates to flow. As a result, the liquid in the main chamber flows to the sub chamber through the orifice. A predetermined damping force is generated by viscous resistance caused by the flow of the liquid, and the engine shake is suppressed (attenuated) by the damping force.
[0009]
The switching means is operated to open the equilibrium chamber to the atmosphere in response to high-frequency vibrations of about 100 Hz to 600 Hz which cause a muffled sound which is a problem during running of the vehicle. As a result, atmospheric pressure is introduced into the equilibrium chamber, and the diaphragm forming the equilibrium chamber freely operates (vibrates). As a result, the liquid in the main chamber flows relatively freely in the main chamber in response to the vibration input from the insulator side. As a result, the dynamic spring constant of the spring system formed by the entire vibration isolator can be kept low. Therefore, the effect of blocking vibration in a high frequency range is enhanced. As described above, according to the present invention, a plurality of types of vibrations are absorbed and cut off by the operation of the switching means including the switching valve and the like.
[0010]
Next, the second aspect of the invention will be described. This is also basically the same as the first aspect. The feature is that a configuration is adopted in which a liquid chamber provided outside the insulator forms a sub-chamber connected to the main chamber via an orifice. Therefore, the elastic diaphragm forming the outer shell of the liquid chamber (sub-chamber) forms a diaphragm, and the space around the elastic diaphragm forms the air chamber in the conventional liquid-filled type vibration damping device. Will be done. By adopting such a configuration, according to the present invention, the liquid-filled type vibration damping device, in which various vibrations including the idling vibration can be cut off by feedforward control, in the longitudinal direction thereof, Can be shortened, and the whole vibration isolator can be made compact.
[0011]
Next, a third aspect of the present invention will be described. This is also basically the same as the first and second aspects. It is characterized in that, in addition to the features described in claim 2, the switching means is directly installed on a rigid plate forming the lower surface of the equilibrium chamber, and a negative pressure or large pressure is applied to the equilibrium chamber. A communication path for introducing air pressure is connected to the switching means by penetrating in the thickness direction of the rigid plate . By adopting such a configuration, as in the case of the second aspect, the whole vibration isolator can be made compact, and a negative pressure or a negative pressure can be introduced into the equilibrium chamber from the switching valve of the switching means. The length of the communication passage for introducing air provided for introducing atmospheric pressure can be shortened. As a result, the flow resistance of the fluid is reduced, and the response to the change in the volume of the equilibrium chamber and the vibration of the diaphragm forming the equilibrium chamber can be improved (improved).
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1 and FIG. 2, the structure of an upper connecting member 6 attached to a vibrating body, a lower connecting member 9 attached to a member on a vehicle body side, and the like, as shown in FIGS. An insulator 2 between the member 6 and the lower connecting member 9 for absorbing and blocking the vibration from the vibrator, and an insulator 2 provided in series with the insulator 2 and filled with a liquid as an incompressible fluid. A vibration isolating mechanism 1 comprising a liquid chamber and the like formed by a main chamber 12 and a sub-chamber 16, and a part of the vibration isolating mechanism 1 which is provided in the main chamber 12 A switching means 3 for performing a switching operation so as to introduce one of the negative pressure and the atmospheric pressure into the chamber 13 continuously or alternately in synchronization with engine vibration; Cut And a control means 5 for controlling the operation, and a second liquid chamber (second liquid chamber) 22 in which a liquid is sealed is provided around the insulator 2. Things.
[0013]
In such a basic configuration, the configuration relating to the first embodiment (first embodiment) has, for example, a configuration as shown in FIG. That is, the insulator 2 is made of a vibration-proof rubber material or the like mainly composed of natural rubber, and one end face of the insulator 2 is integrally connected to the upper connecting member 6 by vulcanization bonding means or the like. Is what it is. A second liquid chamber 22 is provided outside the insulator 2 so as to surround the insulator 2, and a heat-resistant portion of the second liquid chamber 22 where the outer shell is formed is provided. An elastic diaphragm 21 made of EPDM or the like having excellent properties is provided. The vibration isolating mechanism 1 provided in series with the insulator 2 is provided below the insulator 2 continuously with the insulator 2 and has a main chamber 12 filled with liquid. An equilibrium chamber 13 provided at a lower portion of the main chamber 12 through the diaphragm 11 and receiving a negative pressure or an atmospheric pressure based on a switching operation of the switching means 3; A sub-chamber 16 in which a liquid is sealed, and an orifice 15 connecting between the main chamber 12 and the sub-chamber 16, which are provided via a partition plate 14 and a partition plate 14, similarly to the main chamber 12. It is provided below the sub-chamber 16 via a diaphragm 17 and basically comprises an air chamber 18 into which air is always introduced.
[0014]
The switching means 3 operable to introduce the negative pressure or the atmospheric pressure to the equilibrium chamber 13 provided in the main chamber 12 via the diaphragm 11 while appropriately switching the pressure is provided by a switching valve 31 such as a three-way valve. And a solenoid 32 for driving the switching valve 31. A throttle valve 35 for adjusting the introduction speed of the atmospheric pressure with the introduction speed of the negative pressure is provided on the side of the atmospheric pressure introduction port of the switching valve 31 having such a configuration. I have. A communication passage 19 for introducing the negative pressure or the atmospheric pressure is provided between the switching valve 31 of the switching means 3 and the equilibrium chamber 13.
[0015]
Next, the control means 5 for controlling the switching operation of the switching means 3 having such a configuration is constituted by a microcomputer (CPU) or the like formed on the basis of arithmetic means such as a microprocessor unit (MPU). , Detecting vibrations from a vibrating body such as an engine and controlling the switching operation of the switching means 3 according to the vibrations.
[0016]
Next, an operation mode and the like of the present embodiment having such a configuration will be described. That is, the vibration from the vibrating body side is transmitted to the insulator 2 made of a rubber material or the like via the upper connecting member 6 as shown in FIG. Along with this, the insulator 2 vibrates or deforms to absorb or block most of the input vibration. Therefore, most of the vibrations are cut off at the insulator 2, but some of the vibrations are not cut off at the insulator 2 but cut off at the next vibration isolation mechanism 1. Become. Next, a specific operation of the vibration isolation mechanism 1 will be described. First, with respect to idling vibration, by operating the switching means 3, a negative pressure or an atmospheric pressure is alternately introduced at a specific frequency into the equilibrium chamber 13 provided in the main chamber 12. I do. That is, by operating the switching means 3 at a specific frequency, the pressure (volume) in the equilibrium chamber 13 is changed, whereby the main chamber caused by idling vibration inputted through the insulator 2 is changed. Fluctuations in the hydraulic pressure in 12 are absorbed. As a result, the dynamic spring constant of the spring system formed by the insulator 2 and the main vibration isolation mechanism 1 is suppressed to a low value.
[0017]
Further, with respect to the engine shake which is a vibration of a lower frequency than the idling vibration, the liquid is caused to flow in the orifice 15 connecting the main chamber 12 and the sub-chamber 16, thereby The engine shake is absorbed and cut off. That is, since the vibration related to the engine shake has a frequency of about 10 Hz, it is difficult to cut off the vibration by reducing the dynamic spring constant. Therefore, in the present embodiment, as shown in FIG. 1, a constant negative pressure is continuously introduced into the equilibrium chamber 13 forming the vibration isolation mechanism 1 to form the first equilibrium chamber 13. Is pulled down, and the volume of the equilibrium chamber 13 is set to zero. This prevents the volume of the equilibrium chamber 13 from changing. In such a state, when the vibration from the vibrating body is propagated to the insulator 2, the lower surface of the insulator 2 vibrates in response to the vibration, and the liquid in the main chamber 12 is actively subsided. It operates to flow to the chamber 16 side. As a result, the liquid in the main chamber 12 flows to the sub chamber 16 through the orifice 15. A predetermined damping force is generated by viscous resistance caused by the flow of the liquid, and the engine shake is suppressed (attenuated) by the damping force.
[0018]
On the other hand, with respect to a high frequency vibration of about 100 Hz to 600 Hz which causes a muffled sound which is a problem during running of the vehicle, the switching means 3 is operated to bring the equilibrium chamber 13 into a state of being opened to the atmosphere. I do. As a result, atmospheric pressure is introduced into the equilibrium chamber 13, and the first diaphragm 11 forming the equilibrium chamber 13 operates (vibrates) freely. As a result, the liquid in the main chamber 12 relatively freely flows in the main chamber 12 in response to the vibration input from the insulator 2 side. As a result, the dynamic spring constant of the spring system formed by the entire vibration isolator can be kept low. Therefore, the effect of blocking vibration in a high frequency range is enhanced.
[0019]
In such an action of blocking various vibrations, in the present embodiment, as shown in FIG. 1, the portion of the insulator 2 forming the main spring of the vibration isolator is provided in the second liquid chamber (second liquid chamber). Since it is covered with the (chamber) 22 and the elastic diaphragm 21 made of a heat-resistant rubber material, the following effects are further exhibited as compared with the conventional one. That is, even when the present liquid filled type vibration damping device is installed at a high temperature such as an engine room, the portion of the insulator 2 is not directly exposed to the high temperature. Further, since the insulator 2 is provided with the second liquid chamber (second liquid chamber) 22 around the insulator 2, the surface portion thereof is not directly exposed to oxygen in the atmosphere. Therefore, there is no need to particularly consider heat resistance and oxygen deterioration. As a result, even in such a high temperature condition, the portion of the insulator 2 forming the main spring of the vibration isolator can be prevented from increasing its dynamic spring constant due to aging or the like. become. Therefore, in this vibration isolator, feedforward control for blocking various vibrations can be performed by using a simple mechanism. Further, the heat-resistant elastic diaphragm 21 provided on the outside of the insulator 2 forms a skin portion of the second liquid chamber 22 provided around the insulator 2 for regulating the outer periphery thereof. Therefore, the thickness can be reduced. Further, since the present elastic diaphragm 21 is provided separately and independently from the insulator 2 forming the main spring, the present elastic diaphragm 21 is provided with the spring of the entire liquid-sealed type vibration damping device. It does not affect the constant, especially the dynamic spring constant (dynamic spring characteristic). From these facts, it is possible to keep the dynamic spring constant of the entire liquid-filled type vibration damping device low, and to prevent the dynamic spring constant from fluctuating under the influence of heat. become able to.
[0020]
Next, a second embodiment (second embodiment) of the present invention will be described with reference to FIG. This is also basically the same as that described in the first embodiment. That is, a sub-chamber 16 connected to the main chamber 12 through the orifice 15 is formed by a liquid chamber provided outside the insulator 2. Therefore, the elastic diaphragm 21 forming the outer shell of the liquid chamber (sub-chamber) 16 forms the diaphragm 17, and the space around the elastic diaphragm 21 (17) is the space of the first embodiment. The air chamber 18 is formed.
[0021]
The upper extension of the elastic diaphragm 21 (17) having such a structure is formed so as to form a ring-shaped rubber mass 25 at the shoulder of the upper connecting member 6, as shown in FIGS. Has become. This serves as a rebound stopper in the vibration isolator. Further, in the present embodiment, the sub-chamber 16 is formed around the insulator 2, which is a position above the main chamber 12, so that the lower part of the main chamber 12 is formed. In the lower part of the equilibrium chamber 13 provided in the first embodiment, the partition plate 14 in the first embodiment is unnecessary, and a rigid plate 141 is provided instead. A communication path 19 for introducing a negative pressure or an atmospheric pressure into the equilibrium chamber 13 is provided at the rigid plate 141, and at one end of the communication path 19. The switching valve 31 of the switching means 3 is connected. By adopting such a configuration, in the present embodiment, the liquid-filled type vibration damping device that can cut off various vibrations including the idling vibration by feedforward control is provided in the longitudinal direction. Can be shortened. That is, it is possible to reduce the size of the entire liquid-filled type vibration damping device.
[0022]
Next, a third embodiment (third embodiment) of the present invention will be described with reference to FIG. This is also basically the same as the second embodiment. The feature is that, in addition to the second embodiment, the switching means 3 is directly attached to a rigid plate 141 which forms the lower surface of the equilibrium chamber 13. It is. By adopting such a configuration, the present liquid-filled type vibration damping device can be made compact, and a negative pressure or an atmospheric pressure can be supplied from the switching valve 31 of the switching means 3 into the equilibrium chamber 13. Of the communication passage 19 for introducing air, which is provided for introducing air, can be shortened. As a result, the flow resistance of the fluid is reduced, and the response to the change in volume in the equilibrium chamber 13 and the vibration of the diaphragm 11 forming the equilibrium chamber 13 can be improved (improved).
[0023]
【The invention's effect】
According to the present invention, the upper connecting member attached to the vibrating body, the lower connecting member attached to the vehicle body side member and the like, and the vibration from the vibrating body is provided between the upper connecting member and the lower connecting member. An insulator to be shut off, a main chamber provided in series with the insulator and filled with a liquid that is an incompressible fluid, and the main chamber and the orifice are connected so that the liquid flows through an orifice. A sub-chamber, which is formed through a diaphragm in the main chamber via a diaphragm, and comprises an equilibrium chamber or the like formed to introduce one of atmospheric pressure and negative pressure. A vibration mechanism, switching means for performing a switching operation to introduce either the negative pressure or the atmospheric pressure into the equilibrium chamber of the vibration isolation mechanism, and a switching operation of the switching means. Control means for controlling the liquid-filled vibration damping device, comprising: providing a liquid chamber outside the insulator, forming an outer shell of the liquid chamber with an elastic diaphragm having excellent heat resistance. Since the configuration is adopted, the hydraulic pressure fluctuation in the main chamber is controlled in response to various vibration inputs based on the operation of the switching means by the control action of the control means. The dynamic spring constant of the liquid filled type vibration damping device can be reduced, and high damping characteristics in a low frequency range can be formed. As a result, it has become possible to cut off various vibrations including idling vibration.
[0024]
Further, according to the present invention, since a rubber-like heat-resistant elastic diaphragm is provided on the outside of the insulator, the liquid-filled vibration isolator is installed at a high temperature such as an engine room. In this case, the insulator portion made of the vibration-proof rubber material is no longer directly exposed to high temperatures. In addition, since the liquid chamber is provided around the insulator, the surface of the insulator does not directly contact oxygen in the atmosphere. Therefore, as for the insulator forming the main spring in the present invention, it is not necessary to particularly consider heat resistance and degradability against oxygen, etc., and it is only necessary to pursue low dynamic spring characteristics. As a result, it is possible to use a vibration-proof rubber material mainly composed of ordinary natural rubber, and it is possible to suppress an increase in the dynamic spring constant with respect to high-frequency vibration.
[0025]
In addition, a portion of the insulator forming the main spring in the vibration isolator is covered with a heat-resistant elastic diaphragm or the like, and its dynamic spring constant does not fluctuate due to heat or the like in the engine room. Was. Therefore, even when used for many years, the initial set value does not deviate (is deviated), and the simple feedforward control means can cut off various vibrations including idling vibration. You can now plan.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an entire configuration of a first embodiment which is a basic mode of the present invention.
FIG. 2 is a longitudinal sectional view showing an overall configuration of a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing an entire configuration of a third embodiment of the present invention.
FIG. 4 is a longitudinal sectional view showing the entire configuration of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vibration-proof mechanism part 11 Diaphragm 12 Main chamber 13 Equilibrium chamber 14 Partition plate 141 Rigid plate 15 Orifice 16 Sub-chamber 17 Diaphragm 18 Air chamber 19 Communication passage 2 Insulator 21 Elastic diaphragm 22 Second liquid chamber (second liquid chamber)
25 Stopper 3 Switching means 31 Switching valve 32 Solenoid 35 Throttle valve 5 Control means 6 Upper connecting member 9 Lower connecting member

Claims (3)

An upper connecting member attached to the vibrating body, a lower connecting member attached to the vehicle body , an insulator between the upper connecting member and the lower connecting member for absorbing and blocking vibration from the vibrating body, and an insulator for the insulator. A main chamber in which a liquid as an incompressible fluid is sealed, a sub-chamber connected to the main chamber via an orifice so that the liquid flows, and among the atmospheric pressure and the negative pressure be those that are formed through the diaphragm into the room, and one of the ones or formed equilibrium chamber to be introduced Ranaru vibration isolating mechanism, the vibration isolating mechanism and switching means for switching operates to introduce either one of the one of the balancing chamber to the negative pressure or atmospheric pressure parts, and controls the switching operation of said switching means, and the negative pressure in the equilibrium chamber A state continuously introducing one of air pressure, the liquid comprising a negative pressure and the atmospheric pressure above the equilibrium chamber from a control unit for switching into a state to be alternately introduced in a state of being synchronized with the vibration of the vibrating member In a sealed type vibration damping device, a liquid chamber is provided outside the insulator, and an elastic diaphragm excellent in heat resistance is provided at a place where an outer shell of the liquid chamber is formed. Type anti-vibration device. 2. A liquid filled type vibration damping device according to claim 1, wherein a liquid chamber provided outside said insulator is provided with a sub chamber connected to said main chamber via an orifice. Type anti-vibration device. 3. The liquid filled vibration isolator according to claim 2, wherein the switching means is directly installed at a rigid plate forming a lower surface of the equilibrium chamber, and a negative pressure or an atmospheric pressure is introduced into the equilibrium chamber. Wherein the communication path is connected to the switching means by penetrating in the thickness direction of the rigid plate .

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